Sensitizing dyestuffs



United States Patent SENSITIZING DYESTUFFS Adolf Sieglitz, Bad Soden amTaunus, Ludwig Berlin, Frankfurt am Main, and Heinrich Hamal, Ohreu,near Limburg (Lahn), Germany, assignors to Farbwerke HoeclistAktiengesellschaft vormals Meister Lucius & Bruning, Frankfurt am Main,Germany, a corporation of Germany No Drawing. Application January 18,1955, Serial No. 482,673

Claims priority, application Germany January 21, 1954 7 Claims. (Cl.26(l240.4)

The present invention relates to new sensitizing dyestuffs of thecyanine, styryl and merocyanine series; more particularly it relates todyestuffs corresponding to the following general formulae wherein Rrepresents an alkyl or aryl group, A represents a negative radical of aninorganic acid, X stands for O, S, Se or N-alkyl, Y1 and Y2 stand forlower alkyls and Z represents the atoms necessary to complete aheterocyclic radical.

It is known to prepare sensitizing dyestuffs of the cyanine, styryl ormerocyanine series from the quaternary salts of heterocyclic bases, theso called cyclammonium compounds. The dyestufis are obtained accordingto known methods by condensing the said cyclammonium compounds with, forexample, ortho-alkyl esters of aliphatic carboxylic acids or withdialkylaminobenzaldehydes or with methylene-omega-aldehydes of theheterocyclic series or their intermediate compounds which are formed atthe synthesis of these aldehydes, or with heterocyclic bases containingan acetanilido-methylene group and corresponding to the general formulaG n a -r e a reflux condenser.

2,770,620 Patented Nov. 13, 1956 compounds quaternary salts derived from1.2.3.4-tetrazoles and corresponding to the following general formuawherein R1 represents an alkyl or aryl group, R2 represents an alkylgroup, R3 stands for an alkyl group and X means a negative radical of aninorganic acid.

The manufacture of 1.5-dimethyl-1.2.3.4-tetrazole and1-phenyl-5-methyl-1.2.3.4-tetrazole has already been described inliterature (Chemisches Zentralblatt 1926, vol. II, page 2850 andBerichte der Deutschen Chemischen Gesellschaft, vol. 43, page 2908; seealso Richter-Anschiitz, Chemie der Kohlenstoifverbindungen, vol. III,page 170 et seq.). These heterocyclic bases can be transformed intotheir quaternary salts, for example, into the iodoethylate in thefollowing manner:

1-phenyl-5-methyl-1.2.3.4-tetrazole-iodoethylate.

16 grams of l-phenyl-S-methyl-1.2.3.4-tetrazole and 16 grams of ethyliodide are heated for 15 hours in a sealing tube to C. C. Thecrystalline crude product is pulverized, triturated with ethyl acetateand boiled two or three times with ethyl acetate. After each boiling,the product is filtered with suction, while hot. Finally it is washedwith a small quantity of acetone. A white crystalline powder is obtainedwhich melts at 164 C. According to the analysis, 1 mol of ethyl iodidehas been added. On account of the properties of the quaternary salt, thecompound corresponds to the following probable formula In an analogousmanner, there is obtained from 1.5- dimethyl-I.2.3.4-tetrazole the1.5-dimethyl-1.2.3.4-tetrazole-iodoethylate of the following probableformula:

The following examples serve to illustrate the invention but they arenot intended to limit it thereto:

3.16 grams of 1-phenyl-5-methyl-1.2.3.4-tetrazole-iodoethylate aredissolved in a mixture of .15 cc. of dry pyridine, 3.3 cc. ofortho-formic acid triethyl ester, 1.4 cc. of triethylamine and 0.6 cc.of glacial acetic acid, the solution is heated at the boil and boiledfor four hours under After precipitation with ether, the dycstuff isconverted into the perchlorate and recrystallized from acetone. The puredyestuif is obtained in the form of small rod-shaped yellow crystalswhich melt at C. with decomposition. It produces a sensitization maximumat about 4520 Angstrom.

3 Example 2 u C N OOH=OH N CH3 C2115 I Example 3 l I Q a 3.16 grams ofl-phenyl-S-methyl-1.2.3.4-tetrazole-iodoethylate and 4.62 grams of2-(omega-acetanilino-vinyl)- 5.6-dimethylbenzoxazole iodoethylate areheated at the boil in 40 cc. of absolute ethanol. A solution of 2.8 cc.of triethylamine in cc. of absolute ethanol is then added and themixture is boiled for 30 "minutes under a reflux condenser. Aftercooling, the crystals which have separated are filtered off with suctionand Washed with ethanol. After recrystallization from ethanol, yellowcrystals having the form of small obliquely cut off rods are obtainedwhich rnelt at 237 C.238 C. with decomposition. The dyestuflE produces asensitization maximum at about 4920 Angstrom.

Example 4 3.16 grams of l-phenyl-S-methyl-l.2.3.4-tetrazole-iodoethylateare dissolved at 60 C. in 6 cc. of dry pyridine and a solution of 3.08grams of2-(omega-phenyliminoethylidene)-3'ethyl-5.6-dimethyl-benzthiazoline in10 cc. of pyridine is added. Into this mixture 1 cc. of acetic anhydrideis slowly introduced drop by drop at 60 C. The temperature is kept for30 minutes at 60 C.65 C. The reaction product is cooled in the ice-bath,the dye-stuff which has separated is filtered ofi with suction andwashed with acetone. After recrystallization from ethanol orangeredcrystals having the form of lamellae are obtained which melt at 237C.238 C. with decomposition. The dyestuff produces a sensitizationmaximum at about 5 350 Angstrom.

Example 5 3.16 grams of l-phenyl-S-methyl-l.2.3.4-tetrazoleiodoethylateare dissolved at 60 C. in 10 cc. of dry pyridine.

A solution of 3.57 grams of2-(omega-phenylimino-ethylidene)-3-ethyl-S-methoxy-benzseleneazoline in10 cc. of pyridine is then added. Into this mixture 1 cc. of aceticanhydride is slowly introduced drop by drop at 60 C.- 65 C. After aninitial rise of temperature to C., the dyestufi begins to separate inthe form of crystals. Heating is continued for a further 30 minutes, thecrude dyestufif which has been allowed to stand for a prolonged time isthen filtered off with suction, washed with acetone and recrystallizedfrom methanol. Lustrous yellow-red prisms are obtained which melt at 239C. with decomposition. The dyestuif produces a sensitization maximum atabout 5360 Angstrom.

3.16 grams of 1-phenyl-5-methyl-1.2.3.4-tetrazole-iodo ethylate aredissolved at 60 C. in 6 cc. of pyridine. A solution of 3.40 grams of2-(omega-phenylimino-ethylidene)-3-ethyl-5-phenylbenzoxazoline in 8 cc.of pyridine is then added and into this mixture 1 cc. of aceticanhydride is slowly introduced drop by drop at 55 C.60 C. Thetemperature is kept for 15 minutes at 55 C.60 C. After cooling, a smallamount of ether is added and the dyestuif precipitates. It is filteredoff with suction, washed with acetone and recrystallized from ethanol.Orangeyellow crystals having the form of small lamellae are obtained,which melt at 222 C.223 C. with decomposition. The dyestuff produces asensitization maximum at about 4880 Angstrom.

Example 7 V i l N\ /O=OHOH=O 1? G0 OS 01H: 1T1

3.16 grams of l-phenyl-S-methyl-l .2.3.4-tetrazole-iodoethylateaand 2.92grams of 5-(omega-acetanilino-methylene)-3-rnethylrhodanine are heatedat the boil in 60 cc. of absolute ethanol. A solution of 2.8 cc. oftn'ethylamine in 10 cc. of absolute ethanol is then added and themixture is boiled for a further 15 minutes under a reflux condenser.After cooling, the crystals which have separated are filtered ofi withsuction and washed with ethanol. After recrystallization from ethanol,orange-yellow small needles are obtained which melt at C.167 C. withdecomposition. The dyestufi produces a sensitization maximum at about5300 Angstrom.

Example 8 3.16 grams of 1-phenyl-5-methyl-1.2.3.4-tetrazole-iodoethylateand 3.18 grams of 5-(omega-acetanilino-methylene)-3-allyl.rhodan-ine aredissolved in 50 cc. of absolute ethanol, while hot. A solution of 2.8cc. of triethylamine in 5 cc. of absolute ethanol is then added and themixture is heated at the boil for 30 minutes. The dyestufi isrecrystallized from ethanol and then obtained in the form of fine,felted small needles having a yellow-orange color and melting at 182C.-183 C. with decomposition. It produces a sensitization maximum atabout 5300 Angstrom.

Example 9 Example 10 3.16 grams ofl-phenyl-S-methyl-l.2.3.4-tetrazole-iodo ethylate and 3.53 grams of5-(omega-acetanilino-rnethylene)-3-ethylselenorhodanine are heated atthe boil in 80 cc. of ethanol. 2.8 cc. of triethylamine are then addeddropwise and the mixture is boiled for a further 40 minutes under areflux condenser. After cooling, the crude dyestuff is filtered off withsuction and washed with ethanol. After recrystallization from ethanol,orangecolored felted small needles are obtained, which melt at 226C.-227 C. with decomposition. The dyestuif produces a sensitizationmaximum at about 5430 Angstrom.

Example 11 3.16 grams ofl-phenyl-S-methyl-l.2.3.4-tetrazole-iodoethylate and 2.89 grams of5-(omega-acetanilino-methylene)-1.3-dimethylthiohydantoin are heated atthe boil in 40 cc. of absolute ethanol. 2.8 cc. of triethylamine arethen added dropwise and the mixture is boiled for another hour under areflux condenser. After allowing the mixture to stand for a prolongedtime, the crystalline crude dyestufi separates. After recrystallizationfrom ethanol, fine felted small needles having an orange-yellow colorare obtained which melt at 195 C.-196 C. with decomposition. Thedyestutf produces a sensitization maximum at about 5020 Angstrom.

Example 12 ml -lTlCHs N C=CHCH=(lJ-? N 00 os l (J2EE 3.29 grams of1.5-dimethyl-1.2.3.4-tetrazole-iod0ethylate and 2.92 grams of5-(omega-acetanilino-methylene)-3- methylrhodanine are heated at theboil in 70 cc. of absolute ethanol. 2.8 cc. of triethylamine are thenadded dropwise and the mixture is boiled for 3 hours under a refluxcondenser. After cooling, the crude dyestuff' is filtered OE Withsuction, Washed with ethanol and recrystallized from ethanol.Yellow-orange felted small needles are obtained which melt at 257 C.25 8C. with decomposition. The dyestufl produces a sensitization maximum atabout 5200 Angstrom.

Example 13 C1115 If 3.29 grams ofl.5-dimethyl-1.2.3.4tetraz:ole-iodoethylate and 3.18 grams of5-(omega-acetanilino-methylene)-3- allylrhodanine are dissolved in 70cc. of absolute ethanol, the solution is heated at the boil and 2 cc. oftriethylamine are added dropwise. The mixture is boiled for 3 hoursunder a reflux condenser. The resulting crystalline magma is filteredoff with suction, while hot, and washed with ethanol. Afterrecrystallization from ethanol, yellow-orange felted small needles areobtained which melt at 242 0-243 C. with decomposition. The dyestutfproduces a sensitization maximum at about 5220 Angstrom.

3.29 grams of 1.5-dimethyl-1.2.3.4-tetrazoleiodoethylate and 3.53 gramsof 5-(omega-acetanilino-methylene)-3- ethylselenorhodanine are heated atthe boil in 60 cc. of absolute ethanol. 2 cc. of triethylamine are thenadded dropwise and the mixture is boiled for a further minutes under areflux condenser. The crystals which have separated are filtered offwith suction at 65 C.7() C. and washed with ethanol. Afterrecrystallization from ethanol, the dyestuif is obtained in the form oforangecolored felted small needles which melt at 272 C.-273 C. withdecomposition. It produces a sensitization maximum at about 5300Angstrom.

We claim:

1. Sensitizing dyestuffs having a formula selected from the groupconsisting of the following three formulae:

wherein R represents a member of the group consisting 7 8 of lower alkyland phenyl, A represents a negative radical 5. The sensitizing dyestuffcorresponding to the fellowof an inorganic acid, X stands for a memberselected from ing formula I the group consisting of O, S, Se andN-alkyl, Y1 and Y2 stand for lower alkyls and Z represents the atomsneces- N--N- sary to complete a heterocyclic radical. 5 2. Sensitizingdyestutfs corresponding to the following N O=OHOH=OVN'OHS generalformula 1H Iva-R 32115 \N/ N o=on-on=o x 6 I 2 CS 6. The sensitizingdyestufl corresponding to the follow- C235 ing formula 4* fiI-N0Hawherein R represents a member of the group consisting N O=OHOH=OS oflower alkyl and phenyl, X stands for a member selected from the groupconsisting of O, S, Se and N-alkyl, and I Y represents a lower alkylgroup. 2

3. The sensitizing dyestufi corresponding to the following formula 7.The sensitizing dyestufi corresponding to the following formula f T"@lfiT-NOH: N O=OHOH=OS N I I N no os f 00 3 11, \N/ CaHb T 6H; CH2OH=OHg4. The sensitizing dyestnfi corresponding to the follow- ReferencesCited in the file of this patnt ing formula UNITED STATES PATENTS2,689,849 Brooker Sept. 21, 1954

1. SENSITIZING DYESTUFFS HAVING A FORMULA SELECTED FROM THE GROUPCONSISTING OF THE FOLLOWING THREE FORMULAE: